1. The Field of the Invention
Embodiments of the invention relate generally to devices, systems, and methods for removing needles from systems or devices used to close openings in body lumens. More particularly, the present invention relates to devices, systems, and methods for removing needles from systems or devices used for closure of arterial and venous puncture sites accessed through a tissue tract.
2. The Relevant Technology
A number of diagnostic and interventional vascular procedures are now performed translumenally. A catheter is introduced to the vascular system at a convenient access location and guided through the vascular system to a target location using established techniques. Such procedures require vascular access, which is usually established using the well-known Seldinger technique. Vascular access is generally provided through an introducer sheath, which is positioned to extend from outside the patient's body into the vascular lumen. When vascular access is no longer required, the introducer sheath is removed and bleeding at the puncture site stopped.
One common approach for achieving hemostasis (the cessation of bleeding) is to apply external force near and upstream from the puncture site, typically by manual compression. However, the use of manual compression suffers from a number of disadvantages. For example, the manual compression procedure is time consuming, frequently requiring one-half hour or more of compression before hemostasis is achieved. Additionally, such compression techniques rely on clot formation, which can be delayed until anticoagulants used in vascular therapy procedures (such as for heart attacks, stent deployment, non-optical PTCA results, and the like) wear off. The anticoagulants may take two to four hours to wear off, thereby increasing the time required before completion of the manual compression procedure.
Further, the manual compression procedure is uncomfortable for the patient and frequently requires analgesics to be tolerable. Moreover, the application of excessive pressure can at times totally occlude the underlying blood vessel, resulting in ischemia and/or thrombosis. Following manual compression, the patient typically remains recumbent from four to as much as twelve hours or more under close observation to assure continued hemostasis. During this time, renewed bleeding may occur, resulting in blood loss through the tract, hematoma and/or pseudo-aneurysm formation, as well as arteriovenous fistula formation. These complications may require blood transfusions and/or surgical intervention.
The incidence of complications from the manual compression procedure increases when the size of the introducer sheath grows larger, and/or when the patient is anticoagulated. The compression technique for arterial closure can be risky, and is expensive and onerous to the patient. Although trained individuals can reduce the risk of complications, dedicating such personnel to this task is both expensive and inefficient. Nonetheless, as the number and efficacy of translumenally performed diagnostic and interventional vascular procedures increases, the number of patients requiring effective hemostasis for a vascular puncture continues to increase.
To overcome the problems associated with manual compression, the use of bioabsorbable sealing bodies is another example approach that has been proposed to achieve hemostasis. Generally, the use of bioabsorbable sealing bodies relies on the placement of a thrombogenic and bioabsorbable material, such as collagen, at the superficial arterial wall over the puncture site. While potentially effective, the use of bioabsorbable material suffers from a number of drawbacks. For example, bioabsorbable sealing bodies may lack a solid mechanical attachment of the sealing body to the tissue. Due to the lack of a solid mechanical attachment, the sealing body can wander within the tissue tract or move out of the puncture site, thus causing late bleeds. Conversely, if the sealing body wanders and intrudes too far into the arterial lumen, due to the lack of a solid mechanical attachment, intravascular clots and/or collagen pieces with thrombus attached can form and embolize downstream, causing vascular occlusion.
In addition to not having a solid mechanical attachment to the tissue, the sealing bodies may rely upon expandable materials to achieve hemostasis. Again, the expandable materials lack the security of a hard mechanical closure, thus potentially causing late bleeds and prolonging hemostasis.
A further approach to achieving hemostasis is to use a suture to close a puncture site. Although difficult to suture manually, suture applying devices can be used to appropriately place a suture for closing a puncture site. One example suture applying device has a shaft carrying a pair of needles near its distal end. The needles are joined together by a length of suture. The shaft is used to introduce the needles into a lumen of a body structure and the needles pushed back through the lumen wall on either side of a puncture site. After the needles have passed back through the tissue, they are captured on the shaft and drawn proximally away from the body structure. Drawing the needles outward leaves a loop of suture behind to close the puncture site. The loop of suture can then be tied in a knot to complete the closure. Suture applying devices address many disadvantages associated with the use of external force (e.g., digital compression) and with the use of bioabsorbable sealable bodies to achieve hemostasis.
However, the use of suture applying devices also has a number of inefficiencies. Typically, to access a suture in manner that it can be tied off, the needle must be fully removed from the shaft and other components subsequently moved out of the way. However, after needle deployment, suture applying devices are often configured to draw needles proximally only to a point where they are partially exposed at the proximal end of the shaft. To remove needles from the shaft completely, an operator has to use manual force to individually grab the proximal end of each needle (e.g., with a hemostat) and draw it further proximally while also securely holding the shaft. The amount of force required to further draw the needle proximally can sometimes be quite large (and potentially unacceptable).
Some suture applying devices have a separate internal needle holder that can be used to receive a partially exposed needle. The needle holder assists an operator in drawing the needle proximally until the distal end of the needle exits the proximal end of the shaft. However, needle holders often do not sufficiently grip a needle such that it can be efficiently drawn proximally. Additionally, the leverage obtained from using a needle holder is often insufficient to remove a needle from challenging (e.g., calcified or scarred) tissue anatomy.
For at least these reasons, it would be desirable to provide devices and methods for more efficiently removing needles from a suture applying device. It would be particularly desirable to provide devices and methods for efficiently removing needles from a suture applying device used to suture a puncture site associated with a percutaneous vascular procedure.